Abstract: In a lighting device with low intensity light-emitting light sources for incident lighting of areas in a motor vehicle interior, the light sources are distributed in a mount above a converging lens, and aligned via the converging lens onto at least one area to be illuminated in the interior.

Abstract: An illumination device has an illumination means formed by an arrangement of a plurality of semiconductor light sources (2) grouped together to form a field. Sensor elements (3) are arranged at individual positions of the field instead of the semiconductor sources (2). A multifunctional headlight can thus be advantageously created. The headlight can be embodied as a robust, compact, low-space unit. By virtue of the fact that the light sources (2) and the sensor elements (3) do not necessarily use the same lens system (1) i.e. each individual element of the multifunctional headlight can be provided with an individually designed lens system (1), the beam path of the illumination device can be separated from the field of vision of the sensor system and can thus be determined independently over large areas.

Abstract: The invention relates to a wideband illumination device comprising a plurality of semiconductor light sources arranged in a field as a light source, for obtaining a specified light distribution for a vehicle headlight in different operating conditions. Parts of the semiconductor light sources are able to emit light in the visible wavelength region, while others emit light in the non-visible wavelength region. In an especially advantageous manner, individual optical elements are associated with the semiconductor light sources, either individually or in groups, for the targeted production of different radiation characteristics. One such wideband illumination device can be used to create a compact individual headlight by which means both the immediate vicinity and the main beam region in front of a motor vehicle can be illuminated with visible light. The same headlight can also be used to provide light in the non-visible region for using with systems for improving night vision.

Abstract: The invention relates to a novel projector which has an asymmetrical illumination characteristic, and a clear light-dark limit, and uses almost the entire radiation power outputted from the semiconductor light source. To this end, the projector consists of a field of individual semiconductor light sources which are provided with optical elements having a novel form. Said optical elements have as flat a form as possible, such that the light admission inlet of the optical element has an elongated, essentially rectangular form. Furthermore, the optical elements comprise a central region, perpendicular to the light admission surface (F), the projection of said central region into a two-dimensional plane corresponding to a cylindrical two-dimensional Cartesian oval. According to the invention, in order to better use the light emitted from the semiconductor light source, the light emergence surface (G) of the optical element, in the form of a Cartesian oval, is combined with a parabolic reflector (A, B).

Abstract: In order to improve road safety, modern vehicles are provided with sensor systems, which assist the driver of the vehicle either directly or indirectly with respect to the environment surrounding said vehicle, especially with regard to early recognition of dangerous situations, in addition to the usual illumination device. Said systems more particularly include radar systems for detecting distance and the relative speed of objects or night vision improvement systems which are based on illumination of the field of the road environment with infrared light. According to the invention, the illumination means of the illumination device are formed by an arrangement of a plurality of semiconductor light sources (2) grouped together to form a field. Sensor elements (3) are arranged at individual positions of said field instead of said semiconductor sources (2). A multifunctional headlight can thus be advantageously created. Said headlight can be embodied as a robust, compact, low-space unit.

Abstract: An apparatus for determining the alertness of a person, especially a vehicle or machine operator, comprises an image pickup system for recording images of the area of at least one eye of the person, and an image evaluating system which evaluates the images detected by the image pickup system and contains means for detecting the shutting of an eye. The image evaluating system has means for determining pupil size and an evaluating apparatus which determines the alertness according to the eye closing state information obtained by the closed-eye detection means, and according to the pupil size information obtained by the pupil size determining means, with classification into one of at least three stages. The apparatus is used, for example, for determining the alertness of drivers of motor vehicles.

Abstract: In a process and apparatus for determining the condition of a road surface, light backscattered from a road surface is divided into spectral components and the spectral intensity distribution of the backscattered light is analyzed. The wavelength-dependent backscattered light spectrum of a dry road surface is arranged with a mathematical function with free parameters. This function is multiplied by an exponential absorption term which describes the light transmission of a water layer of a defined thickness in order to obtain a mathematical function for the wavelength-dependent distribution of the backscatter intensity (as it impinges on the receiver). Using the actual measured values, the free parameters of the function can then be calculated to obtain a best possible approximation. This among other things, results in a determination of the thickness of the water layer.

Abstract: In a process for determining the condition of a road surface, light is beamed onto the road surface and backscattered light is detected and spectrally analyzed. The light beam contains two light fractions, one having wavelength range which is not significantly absorbed by water/ice and another having a wavelength range which is significantly absorbed by these materials. The first light fraction contains light of several different wavelengths and the spectral analysis includes the determination of an approximation reference curve for the spectral plots of the backscattered light when the road is dry. This is accomplished by using the spectral data of the backscattered light fraction in the wavelength range without significant absorption, and the determination of the difference between the spectral data of the backscattered-light fraction in the other wavelength range and the corresponding data of the approximation reference curve for at least one wavelength.

Abstract: In a process and arrangement for measuring a physical quantity using an optical sensor, for imparting a power modulation proportional to the measured quantity on an effective light flux, the physical quantity being obtained from a ratio of the luminous power of the effective light flux to that of a reference light flux, to achieve a high path neutrality of an optical transmission path, the spectral distribution S(.lambda.) of the effective light flux and the spectral distribution R(.lambda.) of the reference light flux is selected according to the relation: ##EQU1## with .lambda.min<.lambda..sub.1 <.lambda..sub.2 <.lambda. max, the light source being emitting in the wave range between the wavelengths .lambda.min and .lambda.max.